CVE-2026-23269: Linux kernel · apparmor: validate DFA start states are in bounds in unpack_pdb
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High · fixed in 4.15.0-1200.215~14.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.15.0-1200.215~14.04.1, 4.15.0-1191.204~16.04.1, 4.15.0-1200.215~16.04.1 +112
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms that this issue has been fixed by rejecting policies with out-of-bounds start states during unpacking. Users should update to the fixed kernel versions as per their distribution's security notices. No additional mitigation beyond applying the official fix is required.
Description
A vulnerability in the Linux kernel's AppArmor security module was fixed that involved improper validation of DFA start states during policy unpacking. This flaw could cause an out-of-bounds read when start states exceeded the number of states in the DFA, potentially leading to denial of service or local privilege escalation. The issue was addressed by rejecting policies with out-of-bounds start states during unpacking.
References
- ubuntu.com/security/CVE-2026-23269 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23269 (opens in a new tab)
- ubuntu.com/blog/apparmor-vulnerability-fixes-available (opens in a new tab)
- ubuntu.com/security/vulnerabilities/crackarmor (opens in a new tab)
- cdn2.qualys.com/advisory/2026/03/10/crack-armor.txt (opens in a new tab)
- ubuntu.com/security/notices/USN-8141-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8152-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8164-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8165-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8098-10 (opens in a new tab)
- ubuntu.com/security/notices/USN-8201-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8224-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8243-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8261-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8266-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8267-1 (opens in a new tab)